Cisco weight is the Cisco-proprietary BGP path attribute used to influence outbound traffic selection on a local router. Weight is locally significant and is not advertised to BGP neighbors. A higher weight is preferred, and because weight is evaluated early in the Cisco BGP best-path algorithm, it is a direct way to make one exit path preferred over another on the router where the attribute is configured. Local preference also influences outbound traffic, but it is a well-known discretionary BGP attribute used inside an AS and is not Cisco proprietary. MED is primarily used to influence inbound path selection by suggesting to a neighboring AS which entry point should be preferred. AS-path prepending is also typically used for inbound traffic engineering by making a route appear less attractive to external peers. Communities can carry policy information, but they are not the Cisco-proprietary attribute in the list. Therefore, when the requirement specifically asks for the Cisco proprietary BGP path attribute that influences outbound traffic flow, the answer is weight.